The present invention relates to an end fitting for a fiber optic cable for connection to a mating connector.
End fittings of this kind are required whenever a fiber optic cable has to be connected to a light source, to an end of another fiber optic cable or to an optical element or component to be illuminated. When the end of the optical cable is free, for example either because it is not in use or while it is waiting for connection to a mating connector, there is a need to protect the end of the fiber optic cable. This can, for example, be necessary to prevent the end of the fiber optic cable becoming contaminated and thus attenuating the light passing through it. In some systems it can also be necessary in order to prevent injury to the human eye by light emerging from the end of the fiber optic cable.
Various systems are known for such purposes in the prior art. For example German patent specification 42 29 511 C2 discloses a cover for plug connectors for light wave guides. A lug is provided in a mating connector which obscures the light emerging from a light outlet opening. On insertion of the male connector into the mating connector, which is realized as a socket, the lug is bent out of the way so that light from the light source can then be transmitted into the fiber optic cable in the male connector.
In German laying open print DE 44 15 631 a cap member is provided for placement over the end of a connector having two connection sleeves so that the connection sleeves and thus the fiber optic cable ends present within them are protected.
Finally, European patent 0 570 652 B1 discloses a plug connection for optical fibers-comprising at least one plug pin and a socket member for receiving the plug pin with a protective cap being arranged on the plug pin and being movable from a closed position with the end of the optical fibers covered into an open position with the end exposed. In EP 0 570 652 B1 separate means are provided for latching the plug and socket connectors together. In European patent 0 570 652 B2 the overall arrangement is very complicated and thus costly to produce.
It is a principle object of the present invention to provide an end fitting for a fiber optic cable which on the one hand provides protection for the free end of the fiber optic cable when not in use or during assembly and which on the other hand serves a useful purpose after connection of said end fitting to a mating connector.
It is a further object of the present invention to provide an end fitting for a fiber optic cable which has an element protecting the end of a fiber optic cable and which is of simple design, with the element being easy to remove.
It is a yet further object of the present invention to provide a cost-effective and simple end fitting for a fiber optic cable which not only protects the free end of a fiber optic cable prior to installation but also facilitates a connection to a mating connector and secures the completed connection.
In order to satisfy this object there is provided, in accordance with a first embodiment of the invention an end fitting for a fiber optic cable for connection to a mating connector, said end fitting comprising a connector body surrounding an end of at least one fiber optic cable and an element movable relative to said connector body from a first position covering an end of said at least one fiber optic cable to a second position in which said end of said fiber optic cable is aligned with said mating connector and in which said movable element prevents separation of said end fitting and said mating connector.
According to a further aspect of the present invention there is provided a fiber optic end fitting for connection to a mating connector, said end fitting comprising a connector body at least partly surrounding an end of at least one fiber optic cable terminating at a ferrule, a lever, means pivotally mounting said lever on said connector body, said lever having a portion forming a protective cap positioned in front of said ferrule in a first protective position of said lever, at least one guide projection present on one of said lever and said mating connector for entry into a cooperating guide recess on the other one of said mating connector and lever during engagement movement of said end fitting towards said mating connector and cooperating with said guide projection to produce pivotal movement of said guide lever during said movement to expose said ferrule to said mating connector and to move said lever into a locked position in which it prevents disengagement movement of said fiber optic end fitting and mating connector.
Thus, in accordance with the present invention the element or lever provided on the connector body serves, in a first position, to cover over the fiber optic cable, thus protecting it against contamination and protecting users against light emanating from the end of the fiber optic cable. Furthermore, after engagement of the end fitting with a mating connector, the element or lever serves to lock the connections. Thus, the same component is used for two quite distinct functions and results in a particularly simple design, since the number of individual parts required is comparatively small.
It is particularly convenient if the element or the lever is pivotally connected to the connector body since this can be achieved with simple projections provided on the connector body or on the element or lever which engage into corresponding recesses in the other component, i.e. in the element or lever or in the connector body. Such projections and recesses can readily be manufactured by injection moulding processes in a manner well understood in the art of plastic injection moulding. Thus the element or lever can be pivoted from a first position in which it covers over the end of the fiber optic cable into a second position in which it cooperates with the mating connector to lock the end fitting to the mating connector. The lever element is also preferably locked to the connector body in the first position so that the part of the lever or element coupling over the end of the fiber optic cable cannot be accidentally displaced to expose the end of the fiber optic cable.
The element or lever is preferably substantially U-shaped and has a base portion and first and second limbs as well as pivot means disposed between said limbs and said connector body, with the pivot means defining a pivot axis for said element or lever. This embodiment is particularly favorable, since the element or lever and the pivot means are of simple shape and can readily be realized by injection molding.
In a particularly preferred embodiment of the present invention the end fitting further comprises at least one guide feature provided at least one of said first and second limbs, a further guide feature provided at said mating connector, said guide feature and said further guide feature cooperating to move said element from said first position to said second position during engagement movement of said end fitting relative to said mating connector.
More particularly the mating connector preferably comprises a socket having a pair of opposed side walls spaced apart to receive at least a portion of said first and second limbs, and wherein said first guide feature comprises respective outwardly projecting projections on said first and second limbs and wherein said first guide feature comprises guide tracks provided in said opposed said walls and cooperating with said outwardly projecting projections, or vice versa.
The use of elements such as projections and guide tracks provide a simple cost-effective and nevertheless efficient way of providing the locked connection of the present invention.